As shown in a related art schematic of FIG. 1, a typical wireless device 10 such as a cellular telephone includes a digital communication and control system 12 having physical wires or printed circuit board traces (not shown) to facilitate serial communication in a primary bus 14 that is used to convey clock signals, data signals, and other digital signals between a master device 16 and slave devices 18-1 through 18-N. In this exemplary embodiment, the primary bus 14 includes a serial clock (SCLK) line 20 that passes a clock signal to the slave devices 18-1 through 18-N, and a serial data (SDATA) line 22 that passes serial data to and from the slave devices 18-1 through 18-N. The slave devices 18-1 through 18-N may be associated with a sensitive region 24 of the wireless device 10 that is sensitive to spurious signals coupled to the primary bus 14 through operation of the master device 16. For example, harmonics associated with digital pulses used to implement a serial communication protocol can undesirably couple to antennas 26-1 through 26-N within the sensitive region 24.
FIG. 2 is a related art block diagram of the digital communication and control system 12 depicting the primary bus 14 communicatively coupling the master device 16 to the slave device 18-1, along with an LC filter 28 for filtering noise from the SCLK line 20 and an RC filter 30 for filtering noise from the SDATA line 24. In particular, the LC filter 28 and the RC filter 30 each filter out relatively high frequency noise coupled onto the primary bus 14. A disadvantage of the digital communication and control system 12 of FIG. 2 is a relatively high cost due to relatively large component values needed for components L1, C1, R1, and C2 making up the LC filter 28 and the RC filter 30, respectively. Another disadvantage of the digital communication and control system 12 is an occupation of relatively valuable circuit board area by the LC filter 28 and the RC filter 30. Yet another disadvantage is that the master device 16 typically requires a greater than desirable drive capability to drive the primary bus 14 as a result of an increase in capacitance presented by high frequency filters such as those represented by the LC filter 28 and the RC filter 30.
Thus, a new digital communication and control system is needed that reduces spurious signals coupled from the master device 16 to the slave devices 18-1 through 18-N that are controlled via the primary bus 14. There is a further need to minimize exposure of regions such as sensitive region 24 of the wireless device 10 to spurious signals without utilizing expensive filter components, which sacrifice valuable circuit board space and may significantly degrade the overall energy efficiency of the wireless device 10 (FIG. 1).